EN
Analysis of the top-down and bottom-up effects on zooplankton biomass in eutrophic Lake Yeniçağa
Abstract
Several aquatic ecological studies have focused on the contrasting effects of top-down and bottom-up interactions on zooplankton communities. It is essential to comprehend the relative strength of these interactions to evaluate the trophic interactions of pelagic food webs, an area that is still extensively researched due to its complexity. Therefore, we examined the biomass of zooplankton over a one-year period in a freshwater lake that is subject to multiple stressors such as anthropogenic activities, eutrophication. Top-down effects, namely fish biomass, and bottom-up effects, including total phosphorus, total nitrogen, and chlorophyll a concentrations were considered. Structural equation modelling (SEM) was employed to evaluate the relative impact of top-down and bottom-up effects on zooplankton. The SEM analysis revealed that zooplankton is influenced by both top-down and bottom-up effects in Lake Yeniçağa. The biomass of cladocerans was found to have a negative correlation with increasing chlorophyll a, while the Calanoida group was negatively affected by both fish biomass and chlorophyll a from top-down and bottom-up controls. The fish biomass had a positive effect on both Cyclopoida and Rotifera, but only Rotifera showed a negative interaction with chlorophyll a. Direct bottom-up effects of total phosphorus and total nitrogen on chlorophyll a were found, with total nitrogen having a stronger interaction than total phosphorus.
Keywords
Supporting Institution
This study conducted with the financial support of Hacettepe University Scientific Research Project Commission (Project no: FHD-2021-19615).
Project Number
FHD-2021-19615
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Details
Primary Language
English
Subjects
Hydrobiology
Journal Section
Research Article
Publication Date
December 25, 2024
Submission Date
June 3, 2024
Acceptance Date
October 16, 2024
Published in Issue
Year 2024 Volume: 33 Number: 2
